A subscriber who hasn't opened an email in 18 months isn't ignoring you by accident. They forgot they signed up, switched jobs, or check a different inbox now. Keep emailing them anyway and you're not just wasting sends, you're teaching Gmail and Outlook that your emails aren't worth opening. That signal follows you to every other subscriber on your list, including the ones who actually want to hear from you.
This is the problem a sunset policy solves. It's one of the simplest fixes in email marketing, and most small businesses have never set one up.
What a Sunset Policy Actually Is
A sunset policy is a written rule for what happens to subscribers who stop engaging with your emails. Instead of letting dead weight sit on your list forever, you set a timeline: if someone hasn't opened or clicked in X months, you move them through a re-engagement sequence, and if that doesn't work, you remove them.
Think of it like cleaning out a closet on a schedule instead of waiting until it's overflowing. You decide in advance what "inactive" means for your business, what you'll do about it, and when you'll finally let those contacts go.
Most sunset policies have three parts:
- A definition of inactivity (usually based on opens and clicks over a set time period)
- A re-engagement attempt (one or two emails designed to win the subscriber back)
- A removal or suppression step for anyone who still doesn't respond
Why Inactive Subscribers Hurt Deliverability
Email providers like Gmail, Yahoo, and Outlook watch how people interact with your messages. If a large chunk of your list never opens, never clicks, and sometimes marks your email as spam, that provider starts routing your future emails to the junk folder, even for subscribers who love your content.
This is why list size is a vanity metric and engagement rate is the number that actually matters. A list of 5,000 people where 4,000 are active typically performs better, and lands in more inboxes, than a list of 20,000 where only 4,000 are active. Same number of engaged readers, very different sender reputation.
Inactive subscribers also skew your reporting. If you're trying to figure out which subject lines work or which offers convert, a pile of dead contacts makes your open and click rates look worse than they are, and makes it harder to spot what's actually working.
The Spam Complaint Risk
People who signed up two years ago and forgot about you are more likely to hit "report spam" than to unsubscribe. Unsubscribing takes a conscious decision. Reporting spam takes one click and no memory of ever giving you their email. A sunset policy removes these people before they get the chance to damage your sender reputation.
How to Build a Sunset Policy (Step by Step)
You don't need special software to do this, just a plan and a recurring reminder to execute it.
- Define inactivity for your business. For a weekly newsletter, 90 to 120 days of no opens is a reasonable starting point. For a brand that emails monthly, you might stretch that to 6 months. There's no universal number, it depends on your sending frequency.
- Segment your inactive subscribers. Most email platforms let you filter contacts by last open or last click date. Pull everyone who meets your inactivity threshold into a separate list or tag.
- Send a re-engagement sequence. This is typically one to three emails spaced a few days apart, asking directly if they still want to hear from you. Keep it short and give a clear reason to click.
- Give a real deadline. Tell subscribers exactly when they'll be removed if they don't respond. "We'll remove you from our list on [date] unless you click below" performs better than vague language, because it creates urgency.
- Remove or suppress non-responders. Anyone who doesn't open or click your re-engagement emails gets removed from active sending. You can archive them in a separate list rather than deleting the data outright, in case you want to try a different approach later.
- Repeat on a schedule. Run this process quarterly or twice a year. Set a calendar reminder now, because this is the step most people skip.
A Simple Sunset Policy Template
Here's language you can adapt for your own re-engagement email:
> Subject: Still want to hear from us? > > Hi [First Name], > > We noticed you haven't opened our emails in a while. That's okay, inboxes get crowded. > > If you'd still like our updates, click below and we'll keep sending them. > > [Yes, keep me on the list] > > If we don't hear from you by [date], we'll remove you from future emails. No hard feelings, and you're welcome to resubscribe anytime.
This works because it's honest, gives a clear action, and sets an expectation instead of letting the relationship fade out awkwardly.
Common Objections (and Why They Don't Hold Up)
"But I paid to get these subscribers." Sunk cost doesn't change the math. An inactive subscriber costs you deliverability today, regardless of what you spent to acquire them originally.
"What if they come back later?" Some will, and that's fine. A sunset policy doesn't ban people forever, it just stops you from emailing addresses that never open anyway. If someone visits your site again and resubscribes, they start fresh with better standing.
"My list size looks impressive to investors or partners." A big list with poor engagement is a weaker asset than a smaller, active one. Anyone evaluating your email program seriously will look at engagement rate, not raw subscriber count.
Quick Summary: Building Your Sunset Policy
- Decide what "inactive" means for your sending frequency (typically 90 to 180 days without an open)
- Segment inactive subscribers into their own list
- Send a short re-engagement email with a clear deadline
- Remove or suppress anyone who doesn't respond
- Run this process on a recurring schedule, not just once
- Track engagement rate, not list size, as your main success metric
A sunset policy takes an afternoon to set up and a few minutes each quarter to run. In exchange, you protect your sender reputation, get cleaner data on what's actually working, and stop paying to email people who never wanted to hear from you in the first place.